- From: <bugzilla@jessica.w3.org>
- Date: Sat, 05 Mar 2011 02:39:04 +0000
- To: public-html@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12242 Summary: Make UTF-16 an invalid encoding in Polyglot Markup Product: HTML WG Version: unspecified Platform: PC URL: http://dev.w3.org/html5/html-xhtml-author-guide/html-x html-authoring-guide.html#character-encoding OS/Version: All Status: NEW Severity: normal Priority: P2 Component: HTML/XHTML Compatibility Authoring Guide (ed: Eliot Graff) AssignedTo: eliotgra@microsoft.com ReportedBy: xn--mlform-iua@xn--mlform-iua.no QAContact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-wg-issue-tracking@w3.org, public-html@w3.org, eliotgra@microsoft.com * According to HTML5, HTML-parsers must as minimum support UTF-8 and Windows-1252. http://dev.w3.org/html5/spec/parsing.html#character-encodings-0 * While according to XML, XML-parsers must as mininum support UTF-8 and UTF-16. * Polyglot Markup, though, "prefers" UTF-8 (based on HTML5's UTF-8 preference, one should think), but else follows the XML approach and permits both UTF-8 or UTF-16. AS A RESULT, it becomes possible to author "polyglot markup" that works fine in XML-parsers, but which isn't required to work in all and any HTML-parser. We should not declare mark-up that isn't required to work in a HTML-parser as "polyglot markup". Hence we should conclude that UTF-16 should not be a recommended encoding for Polyglot Markup. Discussion: * It was suggested early on, e.g. by e.g. Sam Ruby, that UTF-8 should be the only recommended encoding for polyglot markup. And this can be a very useful suggestion. For instance, it would become a very useful way to "force" many HTML editing programs to default to UTF-8, one should think. It also meets HTML5 which says that new documents SHOULD default to UTF-8. * However, the problem is to justify *exclusion* of UTF-16 by inference from the specs. Because, the use of UTF-16 does not seem to break with the principles behind Polyglot Markup, as laid out in its introduction: http://dev.w3.org/html5/html-xhtml-author-guide/html-xhtml-authoring-guide.html#introduction * Permission to use UTF-16 in polyglot markup is logical, for instance because - UTF-16 can be reliably detected via the BOM, in both XMLand HTML5 - though HTML5 says that, quote: "Using non-UTF-8 encodings can have unexpected results on form submission and URL encodings, which use the document's character encoding by default", the use of non-UTF-8 probably creates form problems in XML-on-the-web too. Thus XML and HTML are probaly in same boat here - and hence it does not seem logical to use against UTF-16 that some form submission problems could occur. * That said, the problems with non-UTF-8 *should* carry *some* weight: e.g. those form submission problems could cause greater problems in XML and it is a small irriation that it is not permitted/ possible to use an explicit character declaration in UTF-16 encoded documents. However, the fact that HTML-parsers aren't required to support UTF-16, is a more fundamental nail in the coffin. Can it have any real-world effect? Not so much when it comes to "big" browsers - they support multiple encodings. But for "simpllistic" parsers of differnent kinds, it could probably have an effect. -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
Received on Saturday, 5 March 2011 02:39:06 UTC